AngularJS Confirm Password Validation

<div ng-controller="confirmCtrl">
   <form name="f1">

      <div>
         <label>Password</label>
         <input type="password" name="EPassword" ng-model="EPassword" required class="form-control" />
      </div>

      <div>
         <label>Confirm Password</label>
         <input type="password" name="ECPassword" ng-model="ECPassword" required compare-to="EPassword" class="form-control" />
         <span class="error" ng-show="f1.ECPassword.$error.compareTo">
            Passwords don't match.
         </span>
      </div>

   </form>
</div>

var app = angular.module("app", []);
app.controller("confirmCtrl", function ($scope)
{
    $scope.user = {
        password: "",
        confirmPassword: ""
    };
});
app.directive("compareTo", function ()
{
    return {
        require: "ngModel",
        scope:
        {
            confirmPassword: "=compareTo"
        },
        link: function (scope, element, attributes, modelVal)
        {
            modelVal.$validators.compareTo = function (val)
            {
                return val == scope.confirmPassword;
            };
            scope.$watch("confirmPassword", function ()
            {
                modelVal.$validate();
            });
        }
    };
});